Fifty-eight young Japanese centropomid fish Lates japonicus were captured from the Hitotsuse River estuary, Miyazaki Prefecture, southeastern Kyushu, Japan, through April to September, 1989, and their sizes of total length (TL) (mean TL 222mm) and body weight (BW) (mean 147g) were recorded. They were reared in a concrete tank (20 ton) until the end of November, 1992, growing to a mean TL of 500mm and mean BW of 1, 825g. The diet of the fish was comprised mainly of raw sardines, shrimp, jack and mackerel. However, negative Feeding efficiency rates and Conversion fac-tors were apparent over the two winter seasons. Feeding activity, based on the mean quantity of food taken per individual, was closely related to water temperature and salinity (S) changes, especially being highest over about 25°C (S 28-30) and reduced to zero below about 16°C (S 34). The species seemed to be strongly resistant to disease, skin erosion and transportation stress, because all individ-uals used for the experiment survived.
